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STUDIES ON STEROID PLANT-GROWTH REGULATOR 27.ENHANCED PRODUCT DIASTEREOMERIC EXCESSES IN ASYMMETRIC DIHYDROXYLATION OF THE(22E,24R)-AND THE(22E,24S)-24-ALKYL STEROIDAL UNSATURATED SIOECHAIN BY USING THE SHARPLESS IMPROVED CHIRAL LIGAND
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作者 Liang Fu HUANG Wei Shan ZHOU Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,345 Lingling Lu,Shanghai 200032 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第12期969-970,共2页
The osmium tetroxide catalyzed asymmetric dihydroxylation of the(22E)- steroidal sidechain is described and an unexpected 8:1 ratio of(22R,23R)and (22S,23S)was obtained from the(22E,24S)-24-ethyl substituted sidechain.
关键词 Chen ALKYL STEROIDAL UNSATURATED SIOECHAIN BY USING THE SHARPLESS IMPROVED CHIRAL LIGAND AND THE STUDIES ON STEROID PLANT-GROWTH REGULATOR 27.ENHANCED PRODUCT DIASTEREOMERIC excesses IN ASYMMETRIC DIHYDROXYLATION OF THE
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Effect of Metabolic Excesses from Dietary Proteins on Blood Profile of Heat-stressed Broilers
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作者 Ibukun Olukorede Popoola Oluwabukola Rashidat Popoola +4 位作者 Ibukun Oluwatobi Busari Ibikunle Funso Olaleru Damilola Deborah Popoola Omobolanle Ayobami David Oluwaseyi Olamide Olajide 《Journal of Zoological Research》 2021年第4期32-40,共9页
Although,dietary proteins play a crucial role in poultry profit maximization,through the sustenance of birds`welfare,growth and development,yet metabolic excesses from crude protein(CP)degradation is detrimental to br... Although,dietary proteins play a crucial role in poultry profit maximization,through the sustenance of birds`welfare,growth and development,yet metabolic excesses from crude protein(CP)degradation is detrimental to broiler chickens(BC)affected by heat stress.This study evaluated the effect of dietary protein levels on blood profile of heat-stressed BC at starter phase(SP)and finisher phase(FP).Arbor Acre BC(n=288)were randomly allotted to four dietary treatments(T1-23%CP;T2-21%CP;T3-19%CP;and T4-17%CP)with six replicate groups in a completely randomized design.Data were subjected to descriptive analysis,analysis of variance(p=0.05)and correlation statistics.Protein intake(PI)was not significantly affected by varying CP in diets at SP,but not at FP,where PI significantly increased with increasing dietary CP.PER had a negative correlation with PCV(r=-0.89,p<0.01),Hb(r=-0.88,p<0.01),RBC(r=-0.93,p<0.01)and PI(r=-0.78,p<0.01).Metabolic excesses including heat dissipation from dietary proteins influenced PCV,Hb,platelets and glucose of heat-stressed broilers. 展开更多
关键词 Crude protein BROILERS Metabolic excesses Heat stress HAEMATOLOGY Protein efficiency
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Dynamic response mechanism and precursor characteristics of gneiss rockburst under different initial burial depths
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作者 LIU Dongqiao SUN Jie +4 位作者 MENG Wen HE Manchao ZHANG Chongyuan LI Ran CAO Binghao 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1004-1018,共15页
To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system... To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real time.The experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial depth.And then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of rockburst.What’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack evolution.Finally,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor. 展开更多
关键词 Traffic Engineering Gneiss Rockburst Crack propagation Excess energy Precursor characteristic
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Density of excess modes below the first phonon mode in four-dimensional glasses
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作者 王利近 胥鼎 张世允 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期483-489,共7页
Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law s... Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law scaling:D(ω)~ω~γ.However,it remains debated on the value of γ at low frequencies below the first phonon-like mode in finitesize glasses.Early simulation studies reported γ=4 at low frequencies in two-(2D),three-(3D),and four-dimensional(4D)glasses,whereas recent observations in 2D and 3D glasses suggested γ=3.5 in a lower-frequency regime.It is uncertain whether the low-frequency scaling of D(ω)~ω^(3.5) could be generalized to 4D glasses.Here,we conduct numerical simulation studies of excess modes at frequencies below the first phonon-like mode in 4D model glasses.It is found that the system size dependence of D(ω) below the first phonon-like mode varies with spatial dimensions:D(ω) increases in2D glasses but decreases in 3D and 4D glasses as the system size increases.Furthermore,we demonstrate that the ω^(3.5)scaling,rather than the ω~4 scaling,works in the lowest-frequency regime accessed in 4D glasses,regardless of interaction potentials and system sizes examined.Therefore,our findings in 4D glasses,combined with previous results in 2D and 3D glasses,suggest a common low-frequency scaling of D(ω)~ ω^3.5) below the first phonon-like mode across different spatial dimensions,which would inspire further theoretical studies. 展开更多
关键词 vibrational density of states excess modes four-dimensional glasses SCALING computer simulation
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Excess non-COVID-19-related mortality among inflammatory bowel disease decedents during the COVID-19 pandemic
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作者 Sarah Rotondo-Trivette Xin-Yuan He +9 位作者 Jamil S Samaan Fan Lv Emily Truong Michaela Juels Anthony Nguyen Xu Gao Jian Zu Yee Hui Yeo Fan-Pu Ji Gil Y Melmed 《World Journal of Gastroenterology》 SCIE CAS 2024年第20期2677-2688,共12页
BACKGROUND The coronavirus disease 2019(COVID-19)pandemic disrupted healthcare in the United States.AIM To investigate COVID-19-related and non-COVID-19-related death and characteristics associated with excess death a... BACKGROUND The coronavirus disease 2019(COVID-19)pandemic disrupted healthcare in the United States.AIM To investigate COVID-19-related and non-COVID-19-related death and characteristics associated with excess death among inflammatory bowel disease(IBD)decedents.METHODS We performed a register-based study using data from the National Vital Statistics System,which reports death data from over 99%of the United States population,from January 1,2006 through December 31,2021.IBD-related deaths among adults 25 years and older were stratified by age,sex,race/ethnicity,place of death,and primary cause of death.Predicted and actual age-standardized mortality rates(ASMRs)per 100000 persons were compared.RESULTS 49782 IBD-related deaths occurred during the study period.Non-COVID-19-related deaths increased by 13.14%in 2020 and 18.12%in 2021[2020 ASMR:1.55 actual vs 1.37 predicted,95%confidence interval(CI):1.26-1.49;2021 ASMR:1.63 actual vs 1.38 predicted,95%CI:1.26-1.49].In 2020,non-COVID-19-related mortality increased by 17.65%in ulcerative colitis(UC)patients between the ages of 25 and 65 and 36.36%in non-Hispanic black(NHB)Crohn’s disease(CD)patients.During the pandemic,deaths at home or on arrival and at medical facilities as well as deaths due to neoplasms also increased.CONCLUSION IBD patients suffered excess non-COVID-19-related death during the pandemic.Excess death was associated with younger age among UC patients,and with NHB race among CD patients.Increased death at home or on arrival and due to neoplasms suggests that delayed presentation and difficulty accessing healthcare may have led to increased IBD mortality. 展开更多
关键词 Inflammatory bowel disease Ulcerative colitis Crohn’s disease COVID-19 Excess death Race SEX DISPARITIES
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Portal vein pulsatility:An important sonographic tool assessment of systemic congestion for critical ill patients
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作者 Stavros Dimopoulos Michael Antonopoulos 《World Journal of Cardiology》 2024年第5期221-225,共5页
In this editorial we comment on the article by Kuwahara et al,published in the recent issue of the World Journal of Cardiology.In this interesting paper,the authors showed a correlation between portal vein pulsatility... In this editorial we comment on the article by Kuwahara et al,published in the recent issue of the World Journal of Cardiology.In this interesting paper,the authors showed a correlation between portal vein pulsatility ratio,examined by bedside ultrasonography,and prognosis of hospitalized patients with acute heart failure.Systemic congestion is being notoriously underdetected in the acutely ill population with conventional methods like clinical examination,biomarkers,central venous pressure estimation and X-rays.However,congestion should be a key therapeutic target due to its deleterious effects to end organ function and subsequently patient prognosis.Doppler flow assessment of the abdominal veins is gaining popularity worldwide,as a valuable tool in estimating comprehensively congestion and giving a further insight into hemodynamics and patient management. 展开更多
关键词 Systemic congestion Organ perfusion Hemodynamics Central venous pressure Point of care ultrasound Venous excess ultrasound
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Point-of-care ultrasonography spotlight:Could venous excess ultrasound serve as a shared language for internists and intensivists?
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作者 Anosh Aslam Khan Hasham Saeed +3 位作者 Ibtehaj Ul Haque Ayman Iqbal Doantrang Du Abhilash Koratala 《World Journal of Critical Care Medicine》 2024年第2期126-136,共11页
Point-of-care ultrasonography(POCUS),particularly venous excess ultrasound(VExUS)is emerging as a valuable bedside tool to gain real-time hemodynamic insights.This modality,derived from hepatic vein,portal vein,and in... Point-of-care ultrasonography(POCUS),particularly venous excess ultrasound(VExUS)is emerging as a valuable bedside tool to gain real-time hemodynamic insights.This modality,derived from hepatic vein,portal vein,and intrarenal vessel Doppler patterns,offers a scoring system for dynamic venous congestion assessment.Such an assessment can be crucial in effective management of patients with heart failure exacerbation.It facilitates diagnosis,quantification of congestion,prognostication,and monitoring the efficacy of decongestive therapy.As such,it can effectively help to manage cardiorenal syndromes in various clinical settings.Extended or eVExUS explores additional veins,potentially broadening its applications.While VExUS demonstrates promising outcomes,challenges persist,particularly in cases involving renal and liver parenchymal disease,arrhythmias,and situations of pressure and volume overload overlap.Proficiency in utilizing spectral Doppler is pivotal for clinicians to effectively employ this tool.Hence,the integration of POCUS,especially advanced applications like VExUS,into routine clinical practice necessitates enhanced training across medical specialties. 展开更多
关键词 Point-of-care ultrasonography ULTRASOUND Venous excess ultrasound Doppler Congestion Heart failure
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Confronting cosmic ray electron and positron excesses with hybrid triplet Higgs portal dark matter
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作者 陈绍龙 Amit Dutta Banik 刘泽坤 《Chinese Physics C》 SCIE CAS CSCD 2022年第6期9-21,共13页
We perform a detailed study of scalar dark matter with triplet Higgs extensions of the Standard Model in order to explain the cosmic ray electron and positron excesses reported by AMS-02 and DAMPE.A detailed analysis ... We perform a detailed study of scalar dark matter with triplet Higgs extensions of the Standard Model in order to explain the cosmic ray electron and positron excesses reported by AMS-02 and DAMPE.A detailed analysis of the AMS-02 positron excess reveals that for different orderings(normal,inverted,and quasi-degenerate)of neutrino mass,the hybrid triplet Higgs portal framework is more favored with respect to the single triplet Higgs portal for TeV scale dark matter.We also show that the resonant peak and continuous excess in DAMPE cosmic ray data can be well explained with the hybrid triplet Higgs portal dark matter when a dark matter sub-halo nearby is taken into account. 展开更多
关键词 dark matter triplet Higgs neutrino mass electron and positron excesses
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Application of Non-Fuel Power Generation Technology in Steel Industry
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作者 Ganglie Zhu Sizhuo Cai Yuxi Wang 《Frontiers of Metallurgical Industry》 2024年第2期1-4,共4页
Through continuous equipment technology transformation and full utilization of Ma Steel's abundant gas,the boiler no longer relies on fuel oil for stable combustion during boiler startup,sliding parameter shutdown... Through continuous equipment technology transformation and full utilization of Ma Steel's abundant gas,the boiler no longer relies on fuel oil for stable combustion during boiler startup,sliding parameter shutdown,and RB,thus achieving safe and stable operation of the boiler under any abnormal working conditions,and achieving good economic and social benefits. 展开更多
关键词 fuel oil excess gas BENEFIT
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ARCADE 2 Spatial Roar, What Theory of Relation Reveals
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作者 Russell Bagdoo 《Journal of Modern Physics》 2024年第5期690-719,共30页
The theory of Relation provides an explanation for the Arcade 2 excess. It assumes that the isotropic radio emission measured by the Arcade 2 Collaboration, which is 5 - 6 times brighter than the expected contribution... The theory of Relation provides an explanation for the Arcade 2 excess. It assumes that the isotropic radio emission measured by the Arcade 2 Collaboration, which is 5 - 6 times brighter than the expected contributions from known extra-galactic sources, is the residue of an immense primitive energy of ordinary matter released by a relativistic bang almost 100 million years after the big bang, which gave the mass-energy the missing gravity to activate contraction. This relativistic bang, via a Lorentz energy transformation, would have released enormous energy held to be the source of the powerful radio noise detected by the NASA researchers. This transformation would have simultaneously triggered the formation of the first stars from dense gas and the reionization of less dense neutral gas. This departs from the idea that continuous reionization began after the formation of the first stars. We emphasize the importance of primordial magnetic fields, which would have generated significant density fluctuations during recombination and acted as a direct seed for cosmic structures. The first stars and galaxies were bathed in strong magnetic fields that gave rise to the radio microwave din (boom) discovered by Arcade 2. These intense magnetic fields alter the trajectory of charged particles zooming near the speed of light, triggering the space roar and emitting radiation that forms a synchrotron radio background. The theory of Relation offers an alternative to the Lambda-CDM cosmological model, which has become the standard model of the big bang, which leads straight to the vacuum catastrophe. 展开更多
关键词 Arcade 2 Excess Relativistic Bang Theory of Relation Lorentz Energy Transformation Cosmic Statics Cosmic Boom Synchrotron Radio Background Primordial Magnetic Fields
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A Case Report on Treating Progressive Supranuclear Palsy with a Combination of Chinese and Western Medicine
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作者 Kai Wu Yongjie Gong +1 位作者 Shan Yang Yalan Yu 《Journal of Clinical and Nursing Research》 2024年第5期23-29,共7页
A case of progressive supranuclear palsy in a 66-year-old woman is presented.The patient complained of“progressive stiffness of both lower limbs for five years,accompanied by choking and coughing for more than 1 year... A case of progressive supranuclear palsy in a 66-year-old woman is presented.The patient complained of“progressive stiffness of both lower limbs for five years,accompanied by choking and coughing for more than 1 year,”and was diagnosed with paralysis in traditional Chinese medicine(TCM),which was characterized by a deficiency of liver and kidney,and phlegm and blood stasis blocking the collaterals.Western medicine diagnosed it as progressive supranuclear palsy.The patient was diagnosed with“Parkinson’s disease”several times in the past and was given“polybasic hydrazide”and“amantadine hydrochloride tablets,”etc.The patient did not have significant symptomatic relief,so she sought further treatment with a combination of traditional Chinese and Western medicine.Based on the concept of deficiency and excess,this disease is categorized as a paralytic disease in Chinese medicine,and the onset of the disease is closely related to the deficiency of the body after a long period of illness,with wind,phlegm,blood stasis,and deficiency as the main pathogenetic mechanism.The treatment is based on the combination of disease and evidence,with traditional Chinese medicine and acupuncture as the main treatments,supplemented by intermediate-frequency pulsed electrical stimulation,transcranial repetitive magnetic stimulation,medicated canisters,wax therapy,traditional Chinese medicine guasha,and acupoint injections.Western medicine is based on symptomatic treatment,and the patient’s symptoms were relieved significantly after the combination of Chinese and Western medicine. 展开更多
关键词 Progressive supranuclear palsy Paralytic disease Diagnosis and treatment Deficiency and excess Combination of Chinese and Western medicine
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Orthodontic-surgical treatment for severe skeletal class Ⅱ malocclusion with vertical maxillary excess and four premolars extraction: A case report 被引量:2
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作者 Yi-Wen Zhou Yan-Yi Wang +3 位作者 Zhi-Feng He Ming-Xing Lu Gui-Feng Li Huang Li 《World Journal of Clinical Cases》 SCIE 2023年第5期1106-1114,共9页
BACKGROUND Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatmen... BACKGROUND Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatment plan for a patient initially treated with four-premolar-extraction camouflage, despite indications for orthognathic surgery.CASE SUMMARY A 23-year-old male sought treatment complaining about his unsatisfactory facial appearance. His maxillary first premolars and mandibular second premolars had been extracted, and a fixed appliance had been used to retract his anterior teeth for two years without improvement. He had a convex profile, a gummy smile, lip incompetence, inadequate maxillary incisor inclination, and almost a class I molar relationship. Cephalometric analysis showed severe skeletal class Ⅱ malocclusion(A point-nasion-B point = 11.5°) with a retrognathic mandible(sella-nasion-B point = 75.9°), a protruded maxilla(sella-nasion-A point = 87.4°), and vertical maxillary excess(upper incisor to palatal plane = 33.2 mm). The excessive lingual inclination of the maxillary incisors(upper incisor to nasion-A point line =-5.5°)was due to previous treatment attempts to compensate for the skeletal class Ⅱ malocclusion. The patient was successfully retreated with decompensating orthodontic treatment combined with orthognathic surgery. The maxillary incisors were repositioned and proclined in the alveolar bone, the overjet was increased, and a space was created for orthognathic surgery, including maxillary impaction, anterior maxillary back-setting, and bilateral sagittal split ramus osteotomy to correct his skeletal anteroposterior discrepancy. Gingival display was reduced, and lip competence was restored. In addition, the results remained stable after 2 years. The patient was satisfied with his new profile as well as with the functional malocclusion at the end of treatment.CONCLUSION This case report provides orthodontists a good example of how to treat an adult with severe skeletal class Ⅱ malocclusion with vertical maxillary excess after an unsatisfactory orthodontic camouflage treatment. Orthodontic and orthognathic treatment can significantly correct a patient’s facial appearance. 展开更多
关键词 Case report Skeletal classⅡmalocclusion Vertical excess Gummy smile Camouflage treatment Orthognathic surgery
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Managing excess PbI_(2)for efficient perovskite solar cells 被引量:1
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作者 Xiaodong Li Jie Sun +2 位作者 Bozhang Li Junfeng Fang Liming Ding 《Journal of Semiconductors》 EI CAS CSCD 2023年第8期7-9,共3页
Perovskite solar cells(PSCs)have attracted much attention due to their low cost,high efficiency and easy processing.Recently,You et al.achieved a record efficiency of 26.1%(certified 25.6%)in PSCs with excellent stabi... Perovskite solar cells(PSCs)have attracted much attention due to their low cost,high efficiency and easy processing.Recently,You et al.achieved a record efficiency of 26.1%(certified 25.6%)in PSCs with excellent stability[1].Excess PbI_(2) in perovskite films was converted into inactive(PbI_(2))2RbCl to avoid its detrimental effect to device stability,while maintaining its positive effect to device efficiency. 展开更多
关键词 PEROVSKITE STABILITY EXCESS
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Point-of-care ultrasound in diagnosis and management of congestive nephropathy 被引量:2
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作者 Michael Turk Thomas Robertson Abhilash Koratala 《World Journal of Critical Care Medicine》 2023年第2期53-62,共10页
Congestive nephropathy is kidney dysfunction caused by the impact of elevated venous pressures on renal hemodynamics.As a part of cardiorenal syndrome,the diagnosis is usually made based on history and physical examin... Congestive nephropathy is kidney dysfunction caused by the impact of elevated venous pressures on renal hemodynamics.As a part of cardiorenal syndrome,the diagnosis is usually made based on history and physical examination,with findings such as jugular venous distension,a third heart sound,and vital signs as supporting findings.More recently,however,these once though objective measures have come under scrutiny for their accuracy.At the same time,bedside ultrasound has increased in popularity and is routinely being used by clinicians to take some of the guess work out of making the diagnosis of volume overload and venous congestion.In this mini-review,we will discuss some of the traditional methods used to measure venous congestion,describe the role of point-of-care ultrasound and how it can ameliorate a clinician’s evaluation,and offer a description of venous excess ultrasound score,a relatively novel scoring technique used to objectively quantify congestion.While there is a paucity of published large scale clinical trials evaluating the potential benefit of ultrasonography in venous congestion compared to gold standard invasive measurements,more study is underway to solidify the role of this objective measure in daily clinical practice. 展开更多
关键词 ULTRASOUND Point-of-care ultrasonography Doppler Venous excess ultrasound score Congestion Hemodynamics Heart failure NEPHROLOGY
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Transcending boundaries:Unleashing the potential of multi-organ point-of-care ultrasound in acute kidney injury 被引量:2
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作者 Aisha Batool Shahzad Chaudhry Abhilash Koratala 《World Journal of Nephrology》 2023年第4期93-103,共11页
Acute kidney injury(AKI)is a clinical syndrome characterized by a rapid increase in serum creatinine levels or a decrease in urine output or both.In spite of thorough history-taking,physical examination,and laboratory... Acute kidney injury(AKI)is a clinical syndrome characterized by a rapid increase in serum creatinine levels or a decrease in urine output or both.In spite of thorough history-taking,physical examination,and laboratory analysis,there are limitations in the diagnostic process and clinical monitoring of AKI.Point-of-care ultrasonography(POCUS),a limited ultrasound study performed by clinicians at the bedside,has emerged as a valuable tool in different clinical settings.In this discussion,we explore the potential of POCUS performed by nephrologists to address specific questions encountered in the diagnosis and management of AKI patients.POCUS not only aids in excluding hydronephrosis but also provides real-time insights into hemodynamics,enabling formulation of individualized treatment plans.Further studies are required to assess the impact of multi-organ POCUS on pragmatic patient outcomes related to AKI,as well as its potential in risk stratification and identification of different levels of AKI severity and pathophysiological signatures. 展开更多
关键词 ULTRASOUND Point-of-care ultrasonography Doppler Venous excess Doppler ultrasound Congestion HEMODYNAMICS Heart failure NEPHROLOGY
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Combining nitrogen effects and metabolomics to reveal the response mechanisms to nitrogen stress and the potential for nitrogen reduction in maize
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作者 LU Yan-li SONG Gui-pei +4 位作者 WANG Yu-hong WANG Luo-bin XU Meng-ze ZHOU Li-ping WANG Lei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第9期2660-2672,共13页
The physiological and metabolic differences in maize under different nitrogen(N)levels are the basis of reasonable N management,which is vital in improving fertilizer utilization and reducing environmental pollution.I... The physiological and metabolic differences in maize under different nitrogen(N)levels are the basis of reasonable N management,which is vital in improving fertilizer utilization and reducing environmental pollution.In this paper,on the premise of defining the N fertilizer efficiency and yield under different long-term N fertilization treatments,the corresponding differential metabolites and their metabolic pathways were analyzed by untargeted metabolomics in maize.N stress,including deficiency and excess,affects the balance of carbon(C)metabolism and N metabolism by regulating C metabolites(sugar alcohols and tricarboxylic acid(TCA)cycle intermediates)and N metabolites(various amino acids and their derivatives).L-alanine,L-phenylalanine,L-histidine,and L-glutamine decreased under N deficiency,and L-valine,proline,and L-histidine increased under N excess.In addition to sugar alcohols and the above amino acids in C and N metabolism,differential secondary metabolites,flavonoids(e.g.,kaempferol,luteolin,rutin,and diosmetin),and hormones(e.g.,indoleacetic acid,trans-zeatin,and jasmonic acid)were initially considered as indicators for N stress diagnosis under this experimental conditions.This study also indicated that the leaf metabolic levels of N2(120 kg ha–1 N)and N3(180 kg ha–1 N)were similar,consistent with the differences in their physiological indexes and yields over 12 years.This study verified the feasibility of reducing N fertilization from 180 kg ha–1(locally recommended)to 120 kg ha–1 at the metabolic level,which provided a mechanistic basis for reducing N fertilization without reducing yield,further improving the N utilization rate and protecting the ecological environment. 展开更多
关键词 long-term experiment nitrogen deficiency nitrogen excess METABOLITES UPLC-QTOF
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Electrical resistivity change of saturated sand during reliquefaction under hammering loading
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作者 Wang Binghui Xiao Xing +2 位作者 Zhang Lei Wang Liyan Jin Dandan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期613-622,共10页
The electrical resistivity method was verified as an optional technique to monitor the change of mesostructure of saturated soils.To investigate the change laws of resistivity and analyze the reliquefaction meso-mecha... The electrical resistivity method was verified as an optional technique to monitor the change of mesostructure of saturated soils.To investigate the change laws of resistivity and analyze the reliquefaction meso-mechanism during the consecutive liquefaction process,five successive impact liquefaction tests were performed in a one-dimensional cubical chamber.The resistivity variation and excess pore water pressure(EPWP)were measured.The results indicate that the excess pore water pressure experienced four stages:quick increase stage,slow dissipation stage,rapid dissipation stage,and stability stage.Meanwhile,a swift decrease of resistivity emerged before the start of the rapid dissipation stage of EPWP,and then an increasing trend of resistivity is demonstrated with the densification of soil.It is proved that the vertical pore connectivity of liquefied sand is better than its random deposit state,based on a comparative study of porosity calculated from the settlement and resistivity of sand after each test. 展开更多
关键词 SAND reliquefaction RESISTIVITY excess pore water pressure MESOSTRUCTURE
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Adsorption of methane onto mudstones under supercritical conditions: Mechanisms, physical properties and thermodynamic parameters
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作者 Yang Wang Hong-Fei Cheng +4 位作者 Qin-Hong Hu Lang-Bo Jia Xi-Meng Wang Sha-Sha Gao Luo-Fu Liu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第1期34-47,共14页
Since the mechanisms of methane-mudstone interactions are important for estimating shale gas reserves,methane adsorption under supercritical conditions of 30 MPa pressure and 303.15,333.15,363.15 K temperatures was st... Since the mechanisms of methane-mudstone interactions are important for estimating shale gas reserves,methane adsorption under supercritical conditions of 30 MPa pressure and 303.15,333.15,363.15 K temperatures was studied to measure the excess methane adsorption in two mudstone samples from Yanchang Formation,Ordos Basin.Excess adsorption features inflection points where the amount of adsorbed gas changes from increasing to decreasing concentrations.Three methods(fixed,slope,and freely fitted density)were applied to calculate the adsorbed-phase density(rad),which was then used to fit the measured excess adsorption.Two criteria,the goodness-of-fit and whether the fitting can obtain reasonable absolute adsorption,were applied to determine the most accurate model.Results indicated that the supercritical Dubinin-Radushkevich(SDR)model with freely fitted rad was the most reasonable model.The volume of adsorbed methane at 363.15 K is close to the micropore(d<2 nm)volume of the corresponding mudstone.Considering the actual geological conditions,the adsorbed gas should be predominantly stored in micropores.Thermodynamic parameters reveal that the methane adsorption on mudstone is a physisorption process that is jointly controlled by the heterogeneity of,and interaction forces between the methane molecule and,the rock surface. 展开更多
关键词 Supercritical methane adsorption Excess adsorption Adsorbed-phase density Adsorption model Thermodynamic feature
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Pore pressure built-up in hydrate-bearing sediments during phase transition: A poromechanical approach
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作者 Shui-Tao Zhang Lin-Lin Wang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第1期482-494,共13页
Due to the density contrast between the hydrate and methane gas,the pore pressure is accumulated in the sediment during the decomposition process of methane hydrate.This accumulation of pore pressure decreases the mag... Due to the density contrast between the hydrate and methane gas,the pore pressure is accumulated in the sediment during the decomposition process of methane hydrate.This accumulation of pore pressure decreases the magnitude of effective stress,further triggering potential geological disasters such as landslide.This paper establishes a theoretical framework to investigate the evolution of fluid pressure in the hydrate-bearing sediments during the decomposition process.This model consists of two parts:an unsaturated thermo-poromechanical constitutive law as well as a phase equilibrium equation.Compared with the existing studies,the present work incorporates the effect of pore volume change into the pressure built-up model.In addition,the capillary effect is considered,which plays a nontrivial role in fine-grained sediments.Based on this model,the evolution of fluid pressure is investigated in undrained conditions.It is shown that four mechanisms mainly contribute to the pressure built-up:the density contrast between decomposing hydrate and producing fluid,the variation of pore volume,the compaction of hydrate due to variation of capillary pressure,and the thermal deformation of pore constituents induced by temperature change.Among these mechanisms,the density contrast dominates the pore pressure accumulation.Under the combined effect of these contributions,the evolution of fluid pressure exhibits a strong nonlinearity during the decomposition process and can reach up to dozens of mega Pascal.Nevertheless,this high-level pressure built-up results in a significant tensile strain,yielding potential fracturing of the sediment. 展开更多
关键词 Methane hydrate Excess fluid pressure Poromechanical Phase equilibrium
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AN INFORMATIC APPROACH TO A LONG MEMORY STATIONARY PROCESS
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作者 丁义明 吴量 向绪言 《Acta Mathematica Scientia》 SCIE CSCD 2023年第6期2629-2648,共20页
Long memory is an important phenomenon that arises sometimes in the analysis of time series or spatial data.Most of the definitions concerning the long memory of a stationary process are based on the second-order prop... Long memory is an important phenomenon that arises sometimes in the analysis of time series or spatial data.Most of the definitions concerning the long memory of a stationary process are based on the second-order properties of the process.The mutual information between the past and future I_(p−f) of a stationary process represents the information stored in the history of the process which can be used to predict the future.We suggest that a stationary process can be referred to as long memory if its I_(p−f) is infinite.For a stationary process with finite block entropy,I_(p−f) is equal to the excess entropy,which is the summation of redundancies that relate the convergence rate of the conditional(differential)entropy to the entropy rate.Since the definitions of the I_(p−f) and the excess entropy of a stationary process require a very weak moment condition on the distribution of the process,it can be applied to processes whose distributions are without a bounded second moment.A significant property of I_(p−f) is that it is invariant under one-to-one transformation;this enables us to know the I_(p−f) of a stationary process from other processes.For a stationary Gaussian process,the long memory in the sense of mutual information is more strict than that in the sense of covariance.We demonstrate that the I_(p−f) of fractional Gaussian noise is infinite if and only if the Hurst parameter is H∈(1/2,1). 展开更多
关键词 mutual information between past and future long memory stationary process excess entropy fractional Gaussian noise
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